Cellular silicon-oxy-carbide glass from foamed silicone resins
AssigneeGeneral Electric Company
InventorsGary M. Renlund, William P. Minnear, Angelo A. Bracco
Life of this patent
Estimating the term…
Abstract
Cellular glass structures are made by foaming select silicone resins. A foaming agent is reacted together with the silicone resin to form a foam that carries the resin as a continuous separate phase distributed throughout the foam. The foaming agent is removed by decomposition, and the remaining silicone resin is crosslinked to retain the foamed structure. The silicone resin is then heated in a non-oxidizing atmosphere at a temperature that will pyrolize the resin. During pyrolysis, the resin densifies to foam a unique glass composition comprised of silicon, oxygen and carbon, where carbon is chemically bonded to silicon, but there are essentially no chemical bonds between carbon and oxygen.
Claims9
A method for preparing a cellular glass structure comprising:
- foaming an intimate mixture of a precursor resin and a foaming agent to form a carrier foam with the resin disposed throughout the carrier foam as a continuous separate phase, the resin being formed into a foamed structure;
- crosslinking the resin to retain the foamed structure without the support of the carrier foam;
- heating the foamed structure to remove the carrier foam by decomposition of the carrier foam;
- and
- heating the foamed precursor resin in a non-oxidizing atmosphere at a temperature that will pyrolize the resin, the heating of the precursor resin being performed for a period of time ending when weight loss from the pyrolizing resin substantially ends, the pyrolized resin forming a cellular glass structure that remains structurally stable at temperatures up to at least 1650.degree. C.
A method for forming a cellular glass structure, comprising:
- forming a solution containing;
- about 0.1 to 2 parts of a precursor resin to 1 part of a foaming agent, a nonpolar organic solvent that is about 10 to 50 weight percent of the foaming agent, a curing agent that is about 0.1 to 4 weight percent of the precursor resin, and water that is about 2 to 250 weight percent of the foaming agent, the solution being formed by dissolving the precursor resin in the solvent, intimately mixing the curing agent and foaming agent with the dissolved resin, and stirring the water into the intimate mixture until the solution becomes creamy in consistency;
- allowing the solution to rise and form a polyurethane foam having the precursor resin disposed therein as a continuous separate phase so that the resin is formed into a foamed structure;
- heating the foam to evaporate water and solvent, to remove the polyurethane by decomposing the polyurethane, and to crosslink the precursor resin so it retains the foamed structure;
- and
- heating the foamed precursor resin in a non-oxidizing atmosphere at a temperature that will pyrolize the resin, the heating of the precursor resin being performed for a period of time ending when weight loss from the pyrolizing resin substantially ends the pyrolized resin forming a cellular glass structure that remains structurally stable at temperatures up to at least 1650.degree. C.
Dependencies are inferred from the claim text.